1. Field of the Invention
This invention relates to an electronic endoscope apparatus whereby a plurality of images can be formed and, for example, an imaged object can be three-dimensionally observed.
2. Related Art Statement
Recently, there is extensively utilized an endoscope whereby organs within a body cavity can be observed by inserting an elongated insertable part into the body cavity or, as required, various curing treatments can be made by using a treating tool inserted through a treating tool channel.
Also, there are suggested various electronic endoscopes wherein such solid state imaging device's as a charge coupled device (CCD) is used for the imaging means.
Now, as in finding an initial cancer, in some case, it is important to discriminate fine concavo-convexes on the surface. However, with the conventional endoscope, the observed or displayed image is plane and it has been difficult to discriminate fine concavo-convexes. Therefore, if the swelling state is so little as to be, for example, of the initial affected state, the affected state will be overlooked and it will be difficult to make a proper diagnosis.
Also, there are defects that, in the case of making a curing treatment by using a treating tool or the like, it will be difficult to positively catch the distance sense and the treatment will be a trouble.
By the way, an endoscope whereby a three-dimensional viewing is possible by using an image guide fiber bundle is mentioned in the gazette of a Japanese utility model publication No. 25360/1973. In this related art example, a pair of image guide fiber bundles for the right eye and left eye are required and there is a problem that the diameter becomes large over the entire length of the insertable part.
Also, in the gazette of a Japanese patent application laid open No. 80221/1986, there is disclosed a technique whereby a three-dimensional viewable image is obtained by a pair of image inverting prisms and a pair of electronic shutters and can be three-dimensionally viewed by spectacled switched and controlled as synchronized with the electronic shutter. However, in this related art example, the light path to the imaging device becomes so long that, if the optical system and imaging device are arranged in the tip part of the insertable part of the actual endoscope, the imaging part for obtaining a three-dimensional picture image will become too long. This imaging part can not be made bendable and therefore there is a defect that the rigid tip part becomes so long that a great pain will be forced to the patient in the case of inserting it.
There are also defects that, in case two independent solid state imaging devices are provided in the tip part of the insertable part, the outside diameter of the tip part will become large, will also force a great pair to the patient in the case of inserting it and the case of being able to use it will be restricted.